6 Answers
6

Yes, the issue is simple. The volume is only associated with the instance, but not mounted.

Check on the AWS console which drive it is mounted as - most likely /dev/sdf.

Then (on ubuntu):

sudo mkfs.ext3 /dev/sdf
sudo mkdir /ebs
sudo mount /dev/sdf /ebs

The first line formats the volume - using the ext3 file system type. This is pretty standard -- but depending on your usage (e.g. app server, database server, ...) you could also select another one like ext4 or xfs.

The second command creates a mount point and the third mounts it into it. This means that effectively, the new volume will be at /ebs. It should also show up in df now.

Last but not least, maybe also add an entry to /etc/fstab to make it reboot-proof.

Assuming that you are using a linux AMI, in your case you have an easy method for increasing the size of the file system:

1) Stop the instance
2) Detach the root volume
3) Snapshot the volume
4) Create a new volume from the snapshot using the new size
5) Attach the new volume to the instance on the same place where the original one was
6) Start the instance, stop all services except ssh and set the root filesystem read only
7) Enlarge the filesystem (using for example resize2fs) and or the partition if needed
8) Reboot

As an alternative you can also launch a new instance and map the instance storage or you can create a new ami combining the two previous steps.